When establishing a collection of several wells in a location in a field where hydrocarbons are being extracted, it is often important to space the wellheads evenly in a predetermined pattern with a view to, among other things, being able to prefabricate components that form interconnections between the wellheads. When such collections of wells are to be established in subsea fields, a prefabricated frame structure is often used, which is put down on the sea floor to form a model or template for how the different wells are to be established relative to each other. In addition, the frame structure functions as a foundation for the wellheads and associated elements. Such a frame structure may weigh several hundred tonnes, and it is complicated and expensive both to transport it to the field and to place it on the sea floor. Because of the great weight, there is also a limit to how many wellheads such a frame structure may comprise.